1. Field of the Invention
The invention relates to a data input device for use with a data processing apparatus, the device comprising a housing that contains a physical member having at least one axis of rotational symmetry and allowing rotational manipulation around any axis with respect to the housing, the device having a sensor for upon the manipulation feeding a sensing signal to the data processing apparatus for thereupon moving a display indicium according to an aggregation of the manipulation on a display. The device includes a controller in response to the sensing signal braking the rotational manipulation. One general realization is as a so-called graphical input device, colloquially called mouse or trackball, which is used to enter commands to a data processing computer or the like. The commands could relate to effecting cursor motions, where activating the cursor at a predetermined position would initiate a stop or specific computer action. Various other user interface features of such a device have been in use. The physical member may have a single axis of rotational symmetry, such as a cylinder. This can likewise be used in the context of a computer. The data processing apparatus may form part of a user appliance not specifically devoted to the data processing per se, such as a radio broadcast tuner. The rotating cylinder could then activate shifting the actually receiving frequency through a prespecified frequency band. Now, although the principal application of the invention is envisaged with a digital data processing apparatus, it may as well be used with apparatus based on analog signalization, such as the above radio broadcast tuner. For brevity, reference is generally had to a data processing apparatus.
2. Description of the Related Art
For use with a computer, a two-dimensional device of this kind is known from U.S. Pat. No. 4,868,549 (Affinito et al.). The reference describes a mouse for use in a video display system for example a personal computer (PC). The mouse serves for the input of coordinates into the system, thus enabling a cursor to be moved across a display screen of the video system. The mouse housing comprises a sphere which performs a rotary motion when the mouse is moved by hand. Via two wheels which are in mechanical contact with the sphere and which are arranged at an angle of 90xc2x0 with respect to one another, a motion of the mouse can be detected and measured in an x-direction as well as a y-direction by rotation of the wheels. Motion sensors are coupled to the shafts of the wheels, thus enabling a motion of the wheels to be transferred to the video system.
The mouse disclosed in the reference also comprises braking means enabling the braking of the wheel in the x-direction as well in the y-direction during motion of the wheels. The motion of the mouse can thus be hampered in a given direction by introduction of a friction which may be greater or smaller in a given direction. In addition to a customary visual feedback (for example, the position of a cursor or an image display screen), the operator also experiences a resistive mechanical feedback by the frictional force on the mouse. The inventors of the present invention have discovered that the feedback effected on the rotation manipulation of the device can be made more sophisticated thereby allowing a wider range of useful applications.
Amongst other things it is an object of the present invention to increase the range of feedback functionality, so that the machine-generated force can effect a richer tactility to the data input device. According to a first aspect of the invention the object is realized in that the controller controls both positive and negative accelerations with respect to the rotational manipulation as governed by the data processing apparatus according to a position signal of the display indicium on the display. In this way, also a feed-forward force could be felt by a human user, in addition to, or as an alternative to a braking or negative acceleration force. The positive and negative accelerations may have a fixed value each, such as +A and xe2x88x92B, respectively wherein A and B could be mutually equal, or alternatively, differ from each other. Also, the range of values may be greater. The effective value of the acceleration can depend on where on the screen the indicium, usually the cursor, is actually located. In this respect, the present invention differs from such realizations in remote handling or robotry, where the description of the remote object to be handled would control the feedback. Also, the invention differs from realization pertaining to a data input device on the basis of a joystick or the like. With such joystick, a force extended on the joystick will move it away from a home position, and the physical offset of the joystick so produced is integrated in time to attain the intended movement of an on-screen indicium. Feedback there would be effected as a force exerted on the joystick. In the present invention, any motion of the rotationally symmetric member translates directly to a movement of the on-screen indicium. Therefore, the force is directly dependent on the on-screen position, and in fact, a non-zero force may be present when the position of the indicium is stationary. It would be possible that the indicium be propelled by the system, so that the system would apply kinetic energy to the physical member. This would be unthinkable in the case of a joystick. Generally, the kinematic functionality of a joystick is widely different from that of mouse/trackball devices.
Advantageously the positive and negative accelerations derive from a potential field mapped on display. The potential field can be mapped as a bit pattern or a set of potential functions. This would allow to realize preferred positions or regions on the display with respect to other positions or regions. The potential may be determined for every pixel or for a subset of all pixels. In the latter case, an operator bit pattern may access the so defined pixels for on the basis of their respective potentials and positions relative to the position of the indicium, calculate an instantaneous sign and value of the acceleration. It would be clear that, for example, motion in an x-direction can now be combined with an acceleration in a y-direction.
Advantageously, the positive and negative accelerations are at least codetermined by an actual velocity of the rotational manipulation. An example would be that during fast motion, the generation of the accelerations is suspended. Only during slow motion, they would be present. This would guide the human user during access of a displayed feature that has fine granularity, for so improving effective dexterity. Gross movements would not need such assistance. Moreover, the machine generated force and the operator generated force are now mutually uncoupled.
Advantageously the sensor allows for detecting an actual total force on the member in at least one coordinate direction. This feature would greatly improve the flexibility of the feedback mechanism. The detection of such actual total force is by itself a conventional embodiment.
Advantageously the sensor allows for detecting an instantaneous velocity of the member with respect to the housing. Likewise, this feature improves verbability of the data input device and its use. Velocity measurement can be realized in a variety of ways.
Advantageously the accelerations are multivated. They may have a finite set of values, or even have a continuous range of values. Sometimes a D/A conversion is necessary.
Advantageously, the device is provided with an assignor for assigning to the member a predetermined virtual rotational inertia. Such inertia is represented by an acceleration that adds to the physical inertia. It has proven to be an excellent device for data input, for training, or for testing operators as to their capacities on a motoric level. The inertia need not be time-uniform and/or spatially uniform. A particular advantage of virtual inertia that is greater than actual physical inertia is that the latter now could be made as small as technically feasible. This may be used to construct the physical member as a lightweight element, making it better suitable for portable and/or miniature devices.
In another embodiment, the device may include at least one electromechanical motor for implementing the brake as well as the accelerator. The brake and the accelerator can be simply implemented by way of electromechanical motors. The motor can be accelerated by application of an excitation current, but it is also possible for the motor to be braked. This depends on the excitation current itself (for example, a positive or negative excitation current), but also on the instantaneous direction of rotation of the motor.
The invention also relates to a data processing apparatus comprising display and a data input device according to the foregoing.
Various other aspects of the invention are recited in dependent claims.